New evohome FW - update WiFi 02.00.17.00 and Application 02.00.17.03

[rvb99]

The boiler is on when the manifold valves are open. Ie the hce80 will turn on the ufh mixer/ circulation pump , open the relevent manifold valves and then call for boiler heat .

I do not understand your system . You should not be feeding the ufh pipes directly from the boiler ( whether opentherm or not) . It should be going through a mixer and that mixer should be preset to provide a manifold temperature of between 35 and 45 deg. This manifold temperature setting is independent of evohome and has nothing to do with any opentherm setting . Your boiler should ideally be sending water at between 70-90 deg and the ufh system mixer should bring this down to 35-45 at the manifold , depending on the temperature you have preset. .

[Giel538]

cv2.jpgcv3.jpg setup.JPG

On this pictures you can see the behaviour of my system. From 10 AM till 11.40 i was playing around a bit so that is not normal behaviour. What i still don't understand is that 2 times (just before 9.30 and around 9.52 the setpoint is set back to 10 degrees and the boiler stopped working (for 2 minutes exactly).

It is also showing that the water temp is always limited at 45 degrees (it does have some small overshoots). The setpoint temp (started at 80) is dropping while the room is heated up (ending on 47).

The room setpoint and the room temperature are not sent by the Evohome. But i think that is because it has multiple zones. With my own thermostat and no zones this 2 values where also sent over opentherm. unfortunately the return water temp data is not available.

@Hengus, It is true that there are differences in the opentherm implementation between boiler manufactures and also which data is available. Here you can find a table the sent message id's based on the type of boilers and/or thermostats: http://otgw.tclcode.com/matrix.cgi#boilers

@rvb99: the 3th picture is coming from the manual. C is a bypass. This is how they build our house, and also the other 50 houses around me

[Dan_Robinson]

OpenTherm control setpoint will be different to the boiler Tmax. Limit your boiler to a maximum of 50 degrees using the buttons on the front. The Evohome will call for 90 degrees but the boiler will max out at 50.

When ambient temperature gets close to the setpoint Evohome will start to throttle back the boiler.

It's a clumsy implementation sadly, but it does work.

I surprised the boiler pump has enough juice to run the ufh directly with no additional pumps.

[lorcanjc]

Outside Temperature at top left of Zone Page and HW blue/red dot now a tank icon. Heat demands are accessed via the installer settings pages.

Found the percentage demand but no outside temperature

[rvb99]

cv2.jpgcv3.jpg setup.JPG

On this pictures you can see the behaviour of my system. From 10 AM till 11.40 i was playing around a bit so that is not normal behaviour. What i still don't understand is that 2 times (just before 9.30 and around 9.52 the setpoint is set back to 10 degrees and the boiler stopped working (for 2 minutes exactly).

It is also showing that the water temp is always limited at 45 degrees (it does have some small overshoots). The setpoint temp (started at 80) is dropping while the room is heated up (ending on 47).

The room setpoint and the room temperature are not sent by the Evohome. But i think that is because it has multiple zones. With my own thermostat and no zones this 2 values where also sent over opentherm. unfortunately the return water temp data is not available.

@Hengus, It is true that there are differences in the opentherm implementation between boiler manufactures and also which data is available. Here you can find a table the sent message id's based on the type of boilers and/or thermostats: http://otgw.tclcode.com/matrix.cgi#boilers

@rvb99: the 3th picture is coming from the manual. C is a bypass. This is how they build our house, and also the other 50 houses around me

Wow ! Which country are you in? That’s the most basic ufh system I’ve ever seen . What is controlling the bypass? I’m not surprised you are having problems.

If definitely not good practice to run direct from boiler without a mixer/pump. In fact I believe there are even special mixers for Opentherm boilers.

[DBMandrake]

So we awoke to find our system borked today, is this likely due to the update?

Attachment 1196Attachment 1197
Attachment 1198

Not borked. It just means the controller recently rebooted and hasn't received any temperature updates from the zones showing hourglasses since the reboot.

This can take up to about 30-60 minutes for heating zones and more than an hour for hot water. Zones at a steady temperature don't send updates very often.

[Dan_Robinson]

Wow ! Which country are you in? That’s the most basic ufh system I’ve ever seen . What is controlling the bypass? I’m not surprised you are having problems.

If definitely not good practice to run direct from boiler without a mixer/pump. In fact I believe there are even special mixers for Opentherm boilers.

I'm guessing Holland.

[SteveP]

looks like the pixies have been busy overnight! I woke this morning to find the outside world blanketed in snow and my evohome fully upgraded I can now set my "posh garden shed/office" electric heating using the new electric heating zone but just need to wade through the snow to carry out the rebinding Have told the wife the immortal words "I'm going out, I might be gone some time"!

[G4RHL]

looks like the pixies have been busy overnight! I woke this morning to find the outside world blanketed in snow and my evohome fully upgraded I can now set my "posh garden shed/office" electric heating using the new electric heating zone but just need to wade through the snow to carry out the rebinding Have told the wife the immortal words "I'm going out, I might be gone some time"!

You got a Man Shed then! Jealous!

[fergie]

That’s interesting. I have an Atag boiler with Opentherm control and I have no manual control over the max flow temperature. Opentherm may well demand 90C for hot water heating but this is limited to the TSet Max (70C in my case) in the boiler profile. When a HR92 demands heat and is out with the TPI temperature range, the boiler flow temperature will slowly but steadily rise to TMax Set and then fall as zones reach their target temperatures. I can play with the manual CH flow setting all day but it does nothing.

It is interesting to note the differences between different boiler and Opentherm bridge combinations.

If would be great if we could then use the new information to help our set ups. For example I think my Atag would be a lot more efficient if evohome called for max heat when there is hot water demand, but called for say only half if the demand was radiators only. It would be even better if we could also control / set some parameters around how it acts.